Dev Blog 131: Alpha 31 released on experimental (the multi-floor update), aircraft cabin cleaning and NG19 postmortem

June 7, 2019

Good day airport CEO and welcome to the 131st development blog, a few days delayed but with good reason. Today, after months of development, we’re launching the first of several upcoming content updates and this first experimental deployment contains Alpha 31 and the multi-floor update. We’ve also been to NG19 and have made good progress on the third and final (for this round) new turnaround service: Aircraft cabin cleaning! So, as you can see, we have a lot of content to dig through and whit no time to spare we’ll just jump into it…

Alpha 31 released on the experimental branch: The multi-floor update

It's happening!!!

It is finally here! We’ve been preparing for the full implementation of multiple floors since it was first voted through by the community but due to the fundamental changes it would bring there was a lot of preexisting work in terms of performance and rendering needed to be done before we could start working on the actual implementation. As we’ve mentioned multiple times before, Airport CEO was never really intended to get as big as it did and because of that we’ve had to own up to a lot of technical debt in general, but especially with this implementation. Enabling cross-floor path-finding was in the end a lot more difficult than we’d originally anticipated, mainly due to the many unique design cases and the fact that we put very few limitations on a player in regards to how they are allowed to construct stuff. There’s also the matter of performance and expanding the path-finding algorithm with new dimensions, which literally puts a new dimension of requirements on making sure that the implementation remains performant in all cases.

But, after a lot of development, and a lot of testing by our brilliant internal focus group we’ve now reached the point where we’re ready to request additional help from you, any publicly facing airport CEO with an ambition of building with multiple floors in an early stage. Alpha 31 and the multi-floor update is when you're reading this live on the experimental branch and the release train with multiple updates in the coming weeks has now left the station. Choo, choo!

To start building multiple terminals you simply use page up or page down to switch floors, and place escalators to enable passengers to transition between them.

 But! Before you switch and check out all of the new tech we’ve developed for the experimental branch we want to make you aware of a few important changes with this update...

IMPORTANT NOTICE: Launching airports saved with Alpha 30 using Alpha 31

Underground conveyor belts needs reconstruction

Due to a completely new underground conveyor belt building system, your old baggage system will not work on Alpha 31 or newer versions unless your airport is adapted or only is constructed using ground floor belts! All underground conveyor belts built with the legacy system will automatically be transferred to the "real" underground floor (one floor down, labeled as “-1”). Alpha 31 features a brand-new conveyor belt escalator system which includes manual placements of escalators to enable underground crossings and better player control. This means that all conveyor belt escalators must be re-placed manually by you in order to get your baggage system up and running again after updating!

We HIGHLY recommend you perform the following steps to restore your save to functioning order:

  1. Open the development panel by pressing F10
  2. Find a toggle called “simulate construction” and make sure it is unchecked
  3. Build conveyor belt escalators where needed to repair the baggage belt connections (found in the build menu where you usually find all buildable conveyor belt items)
  4. Pay close attention to the direction of the escalator (if the escalator should go up or down)
  5. Re-enable baggage service from the operations panel
  6. Finally enable construction again from the development panel

Once your baggage system is restored, some already existing baggage might get stuck on various places on the belts and this is expected, they will automatically be deleted after a while so there is no need to report lingering baggage on a conveyor belt as a bug. Some flights might also get stuck or delayed waiting for undelivered baggage. You will need to dismiss these using the stand panel. After a few flights, given that you’ve re-built your conveyor belt system correctly, the complete baggage system should be up and running again as expected!

Road sidewalks disabled
The areas within the red markings are in Alpha 30 walkable, but not in Alpha 31. Keep this in mind when building in Alpha 31!

Alpha 31 also brings changes to road sidewalk, and will no longer support walkable road sidewalks (the area next to the road which is part of the placed road piece). Instead you must place normal sidewalk and crosswalks to create a path from and to your terminal. This change was made in preparation for the multiple terminal update which will come at a later stage.

We will continue to echo these changes throughout the full deployment of this update, and we’ve also implemented several operational security measures across the game to make you attentive on these changes. For example, airports saved with Alpha 30 but launched with Alpha 31 will have baggage handling automatically disabled and a dialog box popping up making you aware of the important changes happening between Alpha 30 and 31.

While these changes are annoying, they are unfortunately the reality of any early access game development. We’ve done our best to make sure that this transition happens as smooth as possible, considering the huge technical change this is while still keeping save integrity and loadability as one of the highest priorities across the development of the game.

Jetways automatically removed

Jetways now only connect to the first floor, (i.e. the floor above the ground floor) thus any existing stand jetways you have built in your Alpha 30 update will automatically removed and the stand will be converted to a non-jetway stand to accommodate this change. This should however have no apparent impact on your airport from an operational perspective, as the city will provide you with a few stair trucks to accommodate the change.

There’s a lot more to discuss and talk about Alpha 31 and the changes it brings, but we have a lot more to get through in this dev blog so we’ll pause that subject here. With Alpha 31 now available in the open we’ll again start to serve daily updates (mainly during working weekdays) to the experimental branch and once Alpha 31 is stable we’ll start deploying the new turnaround features part of Alpha 32, which are mostly already complete but will be kept back in order to work qualitatively with bugs and roll out more complexity in incremental stages. Our current goal is to make all new content, i.e. Alpha 31 and Alpha32, deployed on the default branch before the Steam summer sale.

Check this forum topic for a full changelog of the experimental Alpha 31 version.

Aircraft cabin cleaning

The last and final new turnaround service for this round is aircraft cabin cleaning, and we’ve been hard at work putting in the assets and initial code required for it to operate. At this stage we’re now occupied with tying the ends together and with catering and de-icing already in place we can happily report that the code is generic and solid enough for this process to be, overall, very swift.

Aircraft cabin cleaning en compasses the process of cleaning out aircraft cabins after a flight and is a natural part of most long-haul flights. In order to offer aircraft cabin cleaning as a turnaround service at your airport you will need to build a waste depot and purchase aircraft cabin cleaning trucks. Once an aircraft has landed and arrived at a stand for turnaround, they will request cabin cleaning and an aircraft cabin cleaning truck will be dispatched. These trucks look a lot like catering trucks in the sense that they park near an aircraft door an extend their cargo hull upwards, however in contrast to catering trucks they of course collect waste units from the aircraft rather than delivering meal units.


An aircraft cabin cleaning truck roaming about in a lone, cold, winter night...

Once an aircraft cabin cleaning truck has filled up with waste, they will head over to a waste depot and offload. In the waste depot, waste will be sorted and made ready for pickup by city-owned garbage trucks. Waste depots have a max capacity of stored waste, so it is important to construct them in a location where they are easily accessed by garbage trucks to avoid any stalls in the overall turnaround process, if a waste depot cannot accept more waste there’s a risk of aircraft cabin cleaning trucks not being able to take on new job tasks as their internal storage also is maxed out; ultimately causing aircraft cabin cleaning to stall across the airport.

As some of you may or may not know...


... Mitchell (the main Airport CEO artist) design all objects in 3D...

... but ultimately render them in 2D allowing for fast-paced workflows and accurate lighting and shadow rendering! Waste depot to the left and catering depot to the right.

Since the waste collection from the waste depot is handled by the nearest city, they own the garbage trucks and as an airport CEO you are in charge of the aircraft cabin cleaning trucks, hence in contrast to the other two new turnaround services, no new business will be introduced with this turnaround service.

By the next dev blog we expect aircraft cabin cleaning to be fully implemented and so we'll have more content to share with you on this front, if not already deployed on the experimental branch. We'll see and keep working!

Nordic Game Conference 2019 postmortem

If you’re one of the 317(!) people that are following the studio via our Instagram account you’re most likely aware of the fact that two weeks ago we attended the annual Nordic Game Conference 2019 here in Malmö. Since none of us in the studio are originally from the game industry we always have the same main goal (in excess of learning stuff of course) when attending these types of fairs: Showcase the game and showcase the studio. This year we were able to get a booth together with an organization that’s supporting local game development, Game Habitat, and even created roll-ups and had a demo station in order to get some visual exposure. We’re happy to report back that all in all there were a lot of aspiring airport CEOs checking out our booth and we got a lot of great insight into how people play the game as we on top of the regular playing did a lot of observation as well. Several of those observations have already been translated into tutorial improvements as part of Alpha 31 and more will come as we continue with the final parts of the localization system.

A photo (uploaded on Instagram) of the NG19 entrance.

All in all we had a great time at NG19, and you can check it all out via our NG19 story highlight over at the Instagram account.

In other news

… serving the all text in Alpha 31 is actually the new localization system, although we’ve disabled the other languages for now as we’re still waiting for the proper professional translation of the game’s content. This might result in a few weird keys popping up here and there instead of the actual text, which we’d as usual love to get bug reports on!

… Steve is steaming ahead in the aircraft factory with the manufacturing of the big birds that are about to come, and have crafted a total of X wide-body aircraft. We’ve also went ahead and prepared for the large aircraft implementation with a large de-icing pad and are currently planning for an overhaul of the various stands to better accommodate vehicle movement and jetway placement as we introduce the new line of large sized aircraft. While still undecided, it’s most likely the large aircraft will be the target of Alpha 33 and something we’ll start working seriously on once Alpha 31 and 32 are stable. Here’s another small teaser below of a bird currently being worked on:


Is it a bird? Is it a plane? Is it a super banana?


… the development strategy is ahead as follows: Alpha 31 stabilization followed by an experimental release of Alpha 32 and the new turnaround services. Both are targeted for a stable release before the Steam summer sale. Once those are out and we’ve a few turns at knocking out bugs and implementing performance improvements, we’ll launch a new feature voting round whist prioritizing development on three new fronts. UI performance and UX improvements, large aircraft implementation and gameplay improvements(including connecting systems, improving feedback loops, giving stuff a purpose, implementing a research tree and more).


Wow. That was a lot and consequently that’s it for this week. We’d love for you to head on out on the experimental branch and test the new multi-floor feature, and we’d love to see your new designs and what new bugs you can produce. Thanks for reading, let us know about your multiple floors and... fly safe!

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